Movable top for material in silo



May 11, 1965 P. H. BEACH MOVABLE TOP FOR MATERIAL IN SILQ I 2 Sheets-Sheet 1 Filed Sept. 25, 1963 Enum- IICIILFlbll-LIIF INVENTOR. PAUL H. BEACH ATTORNEYS May 11, 1965 P. H. BEACH MOVABLE TOP FOR MATERIAL IN SILO Filed Sept. 25, 1963 FIG. 3

2 Sheets-Sheet 2 INVENTOR. PAUL H. BEACH ATTORNEYS United States Patent 3,182,582 MOVABLE TOP FOR MATERIAL IN SILO Paul H. Beach, R0. Box 63, Merrill, Mich. Filed Sept. 25, 1963, Ser. No. 311,444 6 Claims. (Cl. 99235) This invention relates generally to the storage of forage crops, and more specifically to a new and useful silo construction.

In my Patent No. 3,016,814, dated January 16, 1962, I disclose a silo closed at its upper end by a flexible bag comprising the top wall of an air tight storage chamber for silage, the bag being movable downwardly into the chamber when the level of stored crops is lowered as by unloading. In this way, there is provided an air tight storage chamber of substantially no larger volume than the mass of compacted silage therein.

The primary object of this invention is to provide such a movable top wall in an arrangement facilitating the installation and handling thereof.

Another object of this invention is to provide the foregoing in an arrangement which is both simple and relatively inexpensive, while being durable and dependable in operation. I

In one aspect thereof, a silo constructed in accordance with my invention is characterized by the provision of a normally upright supporting structure providing a storage chamber therein, means for loading and unloading the storage chamber, a flexible bag of substantially air impervious material secured adjacent its upper end to the supporting structure in substantially air tight relation thereto adjacent the upper end of the chamber, a shaft across the upper end of the chamber, means connecting the bottom of the bag to the shaft for pulling the bag upwardly and wrapping it around the shaft upon rotation thereof, the shaft being rotatable in opposite directions to alternately wind and unwind the bag, the bag being free, when released, to follow the upper level of stored crops as the same is lowered in the chamber.

The foregoing and other objects, advantages and characterizing features of a silo construction of my invention will become clearly apparent from the ensuing detailed description of an illustrative embodiment thereof, considered in conjunction with the accompanying drawings depicting the same wherein like reference numerals denote like parts throughout, and wherein:

FIG. 1 is a vertical sectional view through a silo incorporating my invention, parts being broken away for ease of illustration and the bag being shown in its fully extended position;

FIG. 2 is a fragmentary detail view thereof, on an enlarged scale;

FIG. 3 is a fragmentary vertical sectional view thereof, on a reduced scale, as viewed from about line 3-3 of FIG. 4, showing the movable top wall only partially unrolled; and

FIG. 4 is a view corresponding to that of FIG. 1 but showing the top wall completely rolled up, for loading the silo.

In the accompanying drawing there is shown a silo, generally designated 1, incorporating the flexible, movable top wall of my invention, generally designated 2. Silo 1 can be of substantially any conventional construction, and is shown as having a cylindrical side wall 3 of concrete stave form on a foundation 4. Silo 1 is equipped with a conventional exterior ladder 5, and with one or more access doors 6 all of which are permanently sealed, so as to be air and moisture tight, except for the top access door 6 through which crops to be stored are loaded into the silo. Silo 1 also has a roof 7, secured on side wall 3 in a conventional manner, as by a flange 8 3,182,582 Patented May 11, 1965 resting on the top of side wall 3 and bolted thereto as indicated at 9.-

A silo constructed or modified in accordance with my invention can be unloaded from either the top or the bot-tom. A bottom unloading mechanism is shown in the drawings, of the type more fully illustrated and described in United States Patent 2,736,461, dated February 28, 1956. Such an unloader has a cutter arm 10 disposed above an endless conveyor 11, which latter is disposed in a trough 12 extending outwardly beyond the side wall 3 of the silo through an opening 13 therein. Opening 13 is otherwise closed by a substantially air tight door 13', and the end of trough 12 normally is closed by a door 12. Arm 10 is provided with a plurality of cutters 14, and is designed to be rotated, and the conveyor 11 driven, by any suitable means such as a motor 15 through appropriate reduction gearing 16, the silage being cut away at the bottom of the silo and delivered to the exterior thereof through the trough 12.

The unloading mechanism of itself is no part of my invention, .and any suitable unloading mechanism can be used.

In carrying out my invention, the upper end of the silo is closed by the flexible bag 2 which complete an air tight chamber, below the bag, for the storage of silage. Such a bag preferably is of a synthetic plastic or rubber material, and should be strong and durable to last for several years and withstand abrasion against the stored crops and against the inner wall surface of the silo. In addition, the bag should be both puncture and tear Iresistant, and should be substantially temperature resistant. That is to say, it should be capable of withstanding wide variations in temperature without loss of flexibility or of its air and moisture impervious nature. It should be rot proof, and resistant to bacterial action, being chemically inert as far as silage acids, alcohols and the like are concerned. should repairs be necessary, and must be of a readily pliable and flexible nature.

Various materials are suitable for the intended purpose, such as for example polyethylene films, the polyester film made by E. I. du Pont de Nemours and CO), Wilmington, Delaware, under the name Mylar, and a poly-vinyl chloride film made by B. F. Goodrich Company.

In the illustrated embodiment, bag 2 comprises a single layer or thickness of such a material.

Bag 2 is secured adjacent its open upper end to silo 1, above access door 6'. In the illustrated embodimentflhis is accomplished by securing the upper end of bag 2 to the inner surface of side wall 3 adjacent the upper end thereof, as illustrated in FIG. 2. To provide an air tight seal between the bag and silo Wall, I first coat the wall with a mastic composition 17, against which the bag 2 is pressed, the seal being completed by a metal ring 18 held in place on the inner periphery of bag 2 and urged against wall 3 by means of lag screws 19 engaging sinkers or anchors 20 in the silo wall 3.

It is a particular feature of my invention that bag 2 is arranged to be rolled up on a drum, and unrolled therefrom. To this end, a drum 21 is mounted on a shaft 22 extending across the upper end of the silo chamber, the shaft being journaled in the silo top 7 by any suitable means, not shown. Flexible connecting means in the form of ropes or cables 23 extend from drum 21 inside bag 2 to the bottom thereof, thereby connecting the bottom of the bag to the drum 21 for winding the former onto the latter. In the illustrated embodiment, three such flexible connectors are provided, lying in a vertical plane containing the axis of drum 21 and bisecting the silo. Ropes 23 are connected at one end to the bag bottom, and at their opposite end to the drum, by any suitable means, not shown.

In addition, it should be readily repairable,

Shaft 22 also carries a spool or drum 24, on which a rope or cable 25 is wound. Rope 25 is connected at one end to spool 24, and extends through an opening 26 in the silo roof 7 and over a pulley 27 mounted on the silo. At its opposite end rope 25 is connected to an operating mechanism, such as the illustrated winch having a drum 28 upon which rope 25 is wound by turning a worm 29 engaging a worm wheel 30 connected to drum 28. An operating handle 31 is provided for rotating worm 29, and the winch mechanism can be enclosed in a housing 32.

Cable 25 is wound on spool 24 in a direction opposite to the direction of winding of cables 23 on drum 21. Therefore, when bag 2 is in its fully extended position, shown in FIG. 1, cable 25 is wound on its spool 24. Upon rotating hand crank 31 in a direction winding cable 25 onto drum 28, the cable 25 unwinds from spool 24, rotating shaft 22 in a direction winding the cables 23 onto their drum 21, and thereafter winding bag 2 onto the drum, beginning with the bottom of the bag. When completely wound upon the drum, bag 2 is in the rolled condition shown in FIG. 4. The weight of bag 2 constantly urges drum 21 in a direction unrolling the bag. This is prevented by Worm 29, until crank 31 is rotated in a direction unwinding cable 25 from its drum 2%. When this is done, bag 2 will unroll itself from the position shown in FIG. 4, winding cable 25 onto spool 24. Thus, unwinding cable 25 from drum 28 releases bag 2 which thereupon unrolls. The bag will unroll, when released, through the intermediate position illustrated in FIG. 3 to its fully extended position shown in FIG. 1, in which the lower end of the bag terminates short of the unloader so as to avoid interference therewith.

To install the top wall of my invention in a silo, the silo is first rendered substantially air tight at its bottom and side wall portions, being recoated and repaired as necessary. The inner surfaces of wall 3 and doors 6, 6' preferably are made as smooth as possible to reduce abrasion on bag 2 and to facilitate falling of silage in the silo upon unloading.

Bag 2 is completely rolled onto drum 21, in which condition it is easily transported and handled. This is a factor of particular importance, because a bag of this size, in such material, will weigh several hundred pounds. The fully rolled bag and drum are installed in place on the silo, cable 25 is connected, and the top of bag 2 is sealed to the upper end of the silo wall in permanent, air tight engagement therewith as shown in FIG. 2.

Silo 1 is filled through top access door 6'. After it is filled the door is closed and sealed so as to be air and moisture tight. Assuming that the silo chamber is completely filled, the upper level of silage will be immediately adjacent bag 2 in its fully wound condition upon drum 21. The gases produced upon fermentation are trapped between the upper level of the silage and the bag 2, and are conserved in the air tight chamber thereby provided.

As the silo is unloaded, the upper level of silage lowers. Cable 25 is unwound from drum 28, permitting bag 2 to lower into the chamber and follow the lowering level of silage. This action is indicated in FIG. 3, for example, where the upper level of silage is indicated at 33, and it will be seen that bag 2 initially unwinds in the form of two bags, or a divided bag, each part of which is free to conform to the silage surface. The farmer can unwind cable 25 to lower bag 2 upon each unloading, or he can do this only periodically, and the bag can rest directly on the silage except where it is separated therefrom by a cushion of inert gases. In either case, it will be seen that there is provided a movable top wall which is or can be lowered to occupy the volume of the storage chamber relinquished by the unloaded silage. As a result, the volume of inert gases remains substantially constant, and there will be substantially no pressure differential on the side wall 3 of the silo. Fluctuations :in temperature and variations in gas volume resulting therefrom are automatically accommodated by the flexible nature of the bag.

The flexible material of the bag will conform to the upper level of silage, regardless of the shapes or attitudes it may assume as the silo is unloaded. To this end, it is another feature of my invention that the bag is flexible throughout.

The silo can initially be only partially filled, if desired, in which event the bag is simply released, to unroll and occupy the upper portion of the silo. Thus, in all cases the movable top wall can be lowered to provide an air tight storage chamber having only the volume occupied by the stored crops and the layer of inert gases above.

If desired, a one way slip clutch 34 can be provided in shaft 22; between drums 21 and 24. Such a clutch could comprise spring pressed clutch plates providing positive engagement for winding the bag onto the drum, while permitting the bag and its drum to unwind independently of cable 25 and its drum 24, should there be suflicient unwinding force on bag 2. This provides a safety factor should the farmer inadvertently forget to lower the bag. The provision of a flexible cable 25 offers a further advantage, in that the farmer can tell the position of the bag in the silo by feeling the tension on the cable, making it unnecessary for him to climb to the top of the silo and visually inspect the bag.

Accordingly, it is seen that my invention fully accomplishes its intended objects. While I have disclosed and described in detail only one embodiment of my invention, that has been done by way of illustration, it being intended that the scope of my invention be defined by the appended claims.

Having fully disclosed and completely described my invention, and its mode of operation, what I claim as new is:

1. A container for the storage of forage crops comprising, a normally upright supporting structure providing a storage chamber therein, means for loading said chamber, means for unloading said chamber, a flexible bag of substantially air impervious material secured adjacent its upper end to said supporting structure in substantially air tight relation thereto adjacent the upper end of said chamber, a shaft across said upper end of said chamber, and means connecting said shaft to the bottom of said bag for pulling the latter upwardly and wrapping saidbag about said shaft upon rotation thereof, said shaft being rotatable in opposite direction to alternately wind and unwind said bag.

2. A container for the storage of forage crops comprising, a normally upright supporting structure providing a storage chamber therein, means for loading said chamber, means for unloading said chamber, a flexible bag of substantially air impervious material secured adjacent its upper end to said supporting structure in substantially air tight relation thereto adjacent the upper end of said chamber, a shaft across said upper end of said chamber, flexible connecting means between said shaft and the bottom of said bag for pulling the latter upwardly and wrapping said bag about said shaft upon rotation thereof, said shaft being rotatable in opposite directions to alternately wind and unwind said bag, said bag being flexible throughout and free when released to follow and conform to the upper level of stored crops as the same is lowered in said chamber.

3. A container for the storage of forage crops, comprising, a normally upright supporting structure providing a storage chamber therein, means for loading said chamber, means for unloading said chamber, a flexible bag of substantially air impervious material secured adjacent its upper end to said supporting structure in substantially air tight relation thereto adjacent the upper end of said chamber, a drum across said upper end of said chamber, flexible connecting means between said drum and the bottom of sald bag interiorly of the latter, and means for rotatmg sald drum in a direction pulling said bag upwardly and wrapping the same about said drum, said drum being rotatable in the opposite direction to unwind said bag to follow the upper level of stored crops as the same is lowered in said chamber.

4. A container for the storage of forage crops comprising, a normally upright supporting structure providing a storage chamber therein, means for loading said chamber, means for unloading said chamber, a flexible bag of substantially air impervious material secured adjacent its upper end to said supporting structure in substantially air tight relation thereto adjacent the upper end of said chamber, a drum across said upper end of said chamber, flexible connecting means extending from said drum through said bag to the bottom thereof, means for rotating said drum in a direction wrapping said bag about said drum, the weight of said bag urging said drum in the opposite direction, said bag being flexible throughout and free when released to follow and conform to the upper level of stored crops as the same is lowered in said chamber.

5. A container for the storage of forage crops comprising, a normally upright supporting structure providing a storage chamber therein, means for loading said chamber, means for unloading said chamber, a flexible bag of substantially air impervious material secured adjacent its upper end to said supporting structure in subbag about said drum, the weight of said bag unwinding the same when said last-named means are released, said bag being flexible throughout and free when released to follow and conform to the upper level of stored crops as the same is lowered in said chamber.

6. A container as set forth in claim 5, wherein said spool is connected to said drum by a one-way slip coupling permitting said bag to unroli without releasing said last-named means upon predetermining force thereon.

No references cited.

RGBERT E. PULFREY, Primary Examiner. 

1. A CONTAINER FOR THE STORAGE OF FORAGE CROPS COMPRISING, A NORMALLY UPRIGHT SUPPORTING STRUCTURE PROVIDING A STORAGE CHAMBER THEREIN, MEANS FOR LEADING SAID CHAMBER, MEANS FOR UNLOADING SAID CHAMBER, A FLEXIBLE BAG OF SUBSTANTIALLY AIR IMPERVIOUS MATERIAL SECURED ADJACENT ITS UPPER END TO SAID SUPPORTING STRUCTURE IN SUBSTANTIALLY AIR TIGHT RELATION THERETO ADJACENT THE UPPER END OF SAID CHAMBER, A SHAFT ACROSS SAID UPPER END OF SAID CHAMBER, AND MEANS CONNECTING SAID SHAFT TO THE 